Contractile proteins will be isolated and characterized from guinea pig epidermis and hair root cells as well as from ME-180 cells, a tissue culture line derived from human keratinizing squamous cell carcinoma. The characterization will be based upon biochemical, ultrastructural and immunological criteria and will be followed by an analysis of the role of these contractile proteins in normal epithelial function and in clinical situations characterized by increased epithelial turnover such as wound healing, psoriasis and ichthyosis.